159 research outputs found
Laser Spectroscopic Measurement of Helium Isotope Ratios
A sensitive laser spectroscopic method has been applied to the quantitative
determination of the isotope ratio of helium at the level of 3He/4He = 10^-7 -
10^-5. The resonant absorption of 1083 nm laser light by the metastable 3He
atoms in a discharge cell was measured with the frequency modulation saturation
spectroscopy technique while the abundance of 4He was measured by a direct
absorption technique. The results on three different samples extracted from the
atmosphere and commercial helium gas were in good agreement with values
obtained with mass spectrometry. The achieved 3-sigma detection limit of 3He in
helium is 4 x 10^-9. This demonstration required a 200 micro-L STP sample of
He. The sensitivity can be further improved, and the required sample size
reduced, by several orders of magnitude with the addition of cavity enhanced
spectroscopy
Matrix-assisted laser desorption/ionization mass spectrometric study of bis(imidazole-1-carboxylate) endfunctionalized polymers
Critical Review of Theoretical Models for Anomalous Effects (Cold Fusion) in Deuterated Metals
We briefly summarize the reported anomalous effects in deuterated metals at
ambient temperature, commonly known as "Cold Fusion" (CF), with an emphasis on
important experiments as well as the theoretical basis for the opposition to
interpreting them as cold fusion. Then we critically examine more than 25
theoretical models for CF, including unusual nuclear and exotic chemical
hypotheses. We conclude that they do not explain the data.Comment: 51 pages, 4 Figure
Proteome analyses using accurate mass and elution time peptide tags with capillary LC time-of-flight mass spectrometry
The design and characteristic features of a new time-of-flight mass spectrometer with a spiral ion trajectory
Mass correlated acceleration in a reflectron MALDI TOF mass spectrometer: an approach for enhanced resolution over a broad mass range
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